Arthrospira sp. growth in photobioreactor : model and simulation of the ISS and ground experiments

International audienceThe Arthrospira-B experiment is the first experiment in space ever allowing the online measurements of both oxygen production rate and growth rate of Arthrospira sp. in batch photobioreactors running in ISS. A 4 bioreactors system was integrated in the ISS Biolab incubator. Each reactor is composed of two chambers (gas/liquid) separated by a PTFE membrane and have been running in batch conditions. Oxygen production is measured by online measurement of the pressure increase in the gas chamber. The experiments are composed of several successive batch cultures for each reactor, performed in parallel on ISS and on ground. In this work, a model for the growth of Arthrospira sp in these membrane photobioreactors is proposed and the simulations results obtained are compared to the experimental results gathered in microgravity and on ground. The photobioreactor model is based on a light transfer limitation model, already used to describe and predict the growth and oxygen production in small to large scale ground photobioreactors. This approach is completed by a model for pH in the liquid phase. This permits to consider the pH increase associated to the bicarbonate consumption for the biomass growth. A membrane gas-liquid transfer model is used to predict the gas pressure increase in the gas chamber. Substrate limitation, pH inhibition, as well as oxygen inhibition must be considered in the biological model. A good fitting is achieved between experimental and simulation results when a good mixing of the liquid phase is maintained. These data show that microgravity has no first order effect on Arthrospira growth rate in a photobioreactor operating in space in ISS

Oxygen Regeneration by Algae Cultivation in Photo-Bioreactor for ISS Cabin Technology Demonstrator

International audienceOxygen regeneration from ambient carbon dioxide is a fundamental technology building block for future life support systems for space applications. BIORAT1 Phase B2 project consists in the development of the Preliminary Design Review (PDR) level design of an On Board Demonstrator (OBD) to be hosted in European Drawer Rack 2(EDR2) facility on board of the ISS. The core of the OBD is a Photo-Bioreactor (PBR) filled with spirulina (Limnospira indica PCC 8005) producing oxygen from carbon dioxide and light by photosynthesis. A Liquid Loop (LL) transports the oxygen & carbon dioxide dissolved into the cultivation medium liquid between the Photobioreactor (PBR) and the ISS cabin ambient air. The Gas Exchange Module (GEM) enables the exchange of Oxygen & Carbon Dioxyde separates the cultivation medium liquid to the ambient air while keeping the liquid inside the LL. The design of this flight hardware is supported by tests results obtained with a Bread Board Model (BBM). In this paper, we present the results of the long duration spirulina cultivation test performed with the BBM. allowing verification of the long term functionality of the PBR & LL including the GEM. The PBR performances together with correlation to the model of the cultivated algae growth and oxygen production are presented. Future development and expected results and perspectives are also presented and discussed

limnospira indica pcc8005 growth in photobioreactor: model and simulation of the iss and ground experiments

limnospira indica pcc8005 growth in photobioreactor2020-11-25International audiencethe arthrospira-b experiment is the first experiment in space ever allowing the online measurements of both oxygen production rate and growth rate of limnospira indica pcc8005 in batch photobioreactors running on-board iss. four bioreactors were integrated in the iss biolab facility. each reactor was composed of two chambers (gas and liquid) separated by a ptfe membrane and was run in batch conditions. oxygen production was monitored by online measurement of the total pressure increase in the gas chamber. the experiments are composed of several successive batch cultures for each reactor, performed in parallel on iss and on ground. in this work, a model for the growth of the cyanobacterium limnospira indica pcc8005 (also known as arthrospira or spirulina) in these space membrane photobioreactors was proposed and the simulation results obtained are compared to the experimental results gathered in space and on ground. the photobioreactor model was based on a light transfer limitation model, already used to describe and predict the growth and oxygen production in small to large scale ground photobioreactors. it was completed by a model for ph prediction in the liquid phase allowing assessment of the ph increase associated to the bicarbonate consumption for the biomass growth. a membrane gas-liquid transfer model is used to predict the gas pressure increase in the gas chamber. substrate limitation is considered in the biological model. a quite satisfactory fit was achieved between experimental and simulation results when a suitable mixing of the liquid phase was maintained. the data showed that microgravity has no first order effect on the oxygen production rate of limnospira indica pcc8005 in a photobioreactor operating in space in zero gravity conditions

BIORAT: Oxygen Recycling between an Algae Photo-bioreactor and a Consumer

International audienc

An Anti-Collision Method of Slip Barrel for Automatic Ship Loading in Bulk Terminal

During the loading operation of a ship loader in bulk terminal, in order to bring bulk cargo, such as coal and ore, precisely into every corner of the cabin and not to raise dust at the same time, the slip barrel mechanism usually is placed fully inside the ship cabin near the cargo as close as possible. However, if too close, it will increase the risk of collision between slip barrel and cargo, which poses a security risk to loading operation